Advanced analyte sensor calibration and error detection

Abstract

Systems and methods for processing sensor data and self-calibration are provided. In some embodiments, systems and methods are provided which are capable of calibrating a continuous analyte sensor based on an initial sensitivity, and then continuously performing self-calibration without using, or with reduced use of, reference measurements. In certain embodiments, a sensitivity of the analyte sensor is determined by applying an estimative algorithm that is a function of certain parameters. Also described herein are systems and methods for determining a property of an analyte sensor using a stimulus signal. The sensor property can be used to compensate sensor data for sensitivity drift, or determine another property associated with the sensor, such as temperature, sensor membrane damage, moisture ingress in sensor electronics, and scaling factors.

What is claimed is: 
     
       1. An analyte sensor system comprising:
 a transcutaneous electrochemical analyte sensor comprising:
 an electrode configured to generate a signal associated with an analyte concentration, wherein the electrode comprises a first portion configured to remain ex vivo during a sensor session, wherein the electrode comprises a second portion configured to be disposed in vivo in a host during the sensor session; and 
 a membrane disposed over at least a portion of the electrode; and 
 
 sensor electronics operably connectable to the transcutaneous electrochemical analyte sensor, wherein the sensor electronics comprise a memory storing information associated with sensor sensitivity, wherein the information associated with sensor sensitivity is based at least in part on information based on a measurement of at least one sensor characteristic of the transcutaneous electrochemical analyte sensor during or after manufacturing of the transcutaneous electrochemical analyte sensor but prior to a sensor session; 
 wherein the measured at least one sensor characteristic is associated with a thickness of the membrane. 
 
     
     
       2. The analyte sensor system of  claim 1 , wherein the sensor electronics are configured to process sensor data measured by the transcutaneous electrochemical analyte sensor to generate displayable sensor information. 
     
     
       3. The analyte sensor system of  claim 1 , further comprising a display device. 
     
     
       4. The analyte sensor system of  claim 1 , wherein the transcutaneous electrochemical analyte sensor is comprises a wire. 
     
     
       5. The analyte sensor system of  claim 1 , wherein the analyte is glucose. 
     
     
       6. The analyte sensor system of  claim 1 , further comprising a temperature sensor configured to measure an ex vivo temperature, wherein the analyte sensor system, during processing of the signal, is configured to perform temperature compensation by accounting for the measured ex vivo temperature. 
     
     
       7. The analyte sensor system of  claim 1 , wherein the sensor electronics are configured to process the signal. 
     
     
       8. The analyte sensor system of  claim 7 , wherein the sensor electronics are configured to process the signal based at least in part on the information associated with sensor sensitivity. 
     
     
       9. The analyte sensor system of  claim 7 , further comprising a receiver, wherein the receiver is configured to further process the processed signal based at least in part on the information associated with sensor sensitivity. 
     
     
       10. The analyte sensor system of  claim 8 , wherein the sensor electronics are configured to transmit the processed signal and the information associated with sensor sensitivity to a receiver for further processing to determine an estimated analyte value. 
     
     
       11. The analyte sensor system of  claim 10 , wherein the receiver is a handheld device, and wherein the handheld device is a smart phone. 
     
     
       12. The analyte sensor system of  claim 1 , wherein the membrane further comprises a polymer having a mediator. 
     
     
       13. The analyte sensor system of  claim 1 , wherein the analyte sensor system is configured to calibrate the transcutaneous electrochemical analyte sensor without reference to any blood glucose data obtained during the sensor session. 
     
     
       14. The analyte sensor system of  claim 1 , wherein the membrane is a membrane system comprising a plurality of different membrane layers. 
     
     
       15. The analyte sensor system of  claim 1 , wherein the membrane is a membrane layer. 
     
     
       16. A non-transient computer readable memory incorporated into an analyte sensor system, the non-transient computer readable memory having instructions stored therein that cause the analyte sensor system to perform the method of:
 storing information associated with sensor sensitivity, wherein the information associated with sensor sensitivity is configured to be used to convert sensor data into estimated analyte values; wherein the information associated with sensitivity is based at least in part on pre-implant information; 
 receiving sensor data generated by a transcutaneous electrochemical analyte sensor, wherein the transcutaneous electrochemical analyte sensor comprises an electrode, wherein the electrode is covered at least in part by a membrane, wherein the electrode comprises a first portion configured to remain ex vivo during a sensor session, wherein the electrode comprises a second portion configured to be disposed in vivo in a host during the sensor session; 
 processing the sensor data generated by the transcutaneous electrochemical analyte sensor to generate displayable sensor information; and 
 wherein the pre-implant information is based at least in part on information from a measurement of at least one sensor characteristic associated with fabrication of the transcutaneous electrochemical analyte sensor, wherein the measured at least one sensor characteristic is associated with a thickness of at least a portion of the membrane. 
 
     
     
       17. The non-transient computer readable memory of  claim 16 , wherein the method further comprises outputting the estimated analyte values on a display. 
     
     
       18. The non-transient computer readable memory of  claim 16 , wherein the analyte is glucose. 
     
     
       19. The non-transient computer readable memory of  claim 16 , wherein the displayable sensor information comprises substantially raw sensor data or transformed sensor data. 
     
     
       20. The non-transient computer readable memory of  claim 16 , wherein the displayable sensor information comprises estimated analyte values. 
     
     
       21. An analyte sensor system comprising:
 a transcutaneous electrochemical analyte sensor comprising:
 an electrode configured to generate at least one data point indicative of analyte concentration, wherein the electrode comprises a first portion configured to remain ex vivo during a sensor session, wherein the electrode comprises a second portion configured to be disposed in vivo in a host during the sensor session; and 
 a membrane disposed on at least a portion of the electrode; and 
 
 a control system configured to:
 use a calibration code associated with the transcutaneous electrochemical analyte sensor, wherein the calibration code is based at least in part on information from a measurement of at least one sensor characteristic of the transcutaneous electrochemical analyte sensor during or after manufacturing of the transcutaneous electrochemical analyte sensor but before a sensor session, wherein the measured at least one sensor characteristic is associated with a thickness of the membrane; 
 receive the at least one sensor data point from the transcutaneous electrochemical analyte sensor; and 
 convert, in real-time, the at least one sensor data point to an estimated analyte value. 
 
 
     
     
       22. The analyte sensor system of  claim 21 , wherein the control system is further configured to display the estimated analyte value. 
     
     
       23. The analyte sensor system of  claim 21 , wherein the analyte is glucose. 
     
     
       24. The analyte sensor system of  claim 21 , further comprising a temperature sensor configured to measure an ex vivo temperature, wherein the control system is configured to convert, in real-time, the at least one sensor data point to an estimated analyte value, based at least in part on the measured ex vivo temperature. 
     
     
       25. The analyte sensor system of  claim 21 , wherein the membrane is a membrane system comprising a plurality of different membrane layers. 
     
     
       26. The analyte sensor system of  claim 21 , wherein the membrane is a membrane layer. 
     
     
       27. The analyte sensor system of  claim 21 , further comprising sensor electronics configured to operably connect with the sensor. 
     
     
       28. The analyte sensor system of  claim 27 , wherein the control system is a component of the sensor electronics. 
     
     
       29. The analyte sensor system of  claim 27 , wherein the sensor electronics is configured to operably connect with a receiver, wherein the control system is a component of the receiver. 
     
     
       30. The analyte sensor system of  claim 29 , wherein the control system is a software on the receiver.